@screen-width: 750;
#top-box{
	width: 100vw; 
	height: calc(490/@screen-width*100vw);
	background: url('../images/mobile/top.jpg') 0 0 no-repeat;
	background-size: contain;
}

#count_down {
    border: 3px solid #e60012;
    border-radius: 15px;
    width: calc(323/@screen-width*100vw);
    height: calc(56/@screen-width*100vw);
    line-height: calc(56/@screen-width*100vw);
    color: #fff;
    font-size: calc(24/@screen-width*100vw);
    font-family: "微软雅黑", arial;
    text-align: center;
    position: absolute;
    top: calc(377/@screen-width*100vw);
    left: calc(33/@screen-width*100vw);
    background-color: rgba(0,0,0, 0.28);
}

#count_down:before {
    content: "直播倒计时  ";
    font-size: calc(20/@screen-width*100vw);
}